Field of the Invention
The present invention relates to an image reading apparatus. More particularly, the present invention relates to an image reading apparatus with a projector, which is configured to read an image of an original at a high resolution.
Description of the Related Art
An image reading apparatus with a projector is hitherto known.
In Japanese Patent Application Laid-Open No. 2013-76923, there is disclosed a projection apparatus capable of changing an illumination range and an illumination intensity distribution in illumination produced by a projector.
Further, in Japanese Patent Application Laid-Open No. 2004-347775, there is disclosed a projector capable of intentionally blurring a pixel interval in order to improve visual performance of a projected image.
However, in an image reading apparatus that uses in combination a related-art projector as an apparatus configured to illuminate an object, when a resolution of the image reading apparatus exceeds a resolution of the projector, information on minute illumination unevenness is superimposed on original image information.
Examples of a cause of the minute illumination unevenness include a streak between display pixels of the projector. The streak is caused by an influence of an electrode or the like that forms an image displaying element such as a liquid crystal panel, and therefore cannot be eliminated even when the streak can be reduced by being subjected to thinning or the like. Further, in addition to the liquid crystal panel, the same applies to an image displaying element configured to drive a fine mirror surface.
Therefore, the present invention provides an image reading apparatus capable of reading an image of an original at a high resolution by an image pickup unit by reducing an influence of a dark line included in a projection image on an original placing stand, which is ascribable to a displaying element included in a projecting unit and is to be exerted on an original placed on the original placing stand.